Bruce M

at 105MPH, then check engine light flashes a bunch of times, then goes off.

Weird part was, it did not happen in 4th, which I ran up to 120. Only 5th or 6th gear at just over 100.

Last time it happened, check engine light stayed on, and remains lit. Will try to VAG tomorrow.

Feels like minor misfire, gets a bit worse, power down some, then check engine light. Boost feels strong and car feels fast up until it happens. At next test, car feels fine with normal turbo boost/sounds until it hits the hesitation "wall".

Any ideas before I check codes? Damn, and I am going to Summit Point on Saturday. Figures! Only thing I did not do was check it with water injection disconnected. Will try that tomorrow, but not too many places to test it safely north of 100mph.

Bruce

Funkweasel

$10 says its just misfire codes.

Bruce M

Which means find source of misfire....plugs, bad gas, too much water, etc?

Funkweasel

turn the w/i off you'll see for sure. If not you'll be able to do some logging and of course the misfire codes will tell you which cylinders. You spend a lot of time at fairly low rpms and high boost in 5th and 6th, so if you're injecting according to fuel injector duty cycle...well some of the chips are on the silly side of too much fuel anyway. Then you'd be injecting quite a bit of water based on that without the real need for it.

Bruce M

Gotcha.....running x-chip. I am matching injector duty cycle, so might be the problem. Thanks!

Funkweasel

<img src="http://pictureposter.audiworld.com/16111/x_inj_time.jpg">

Bruce M

I am moron....explain chart please?

Funkweasel

what the pulsewidths would be if the injectors were running 100% duty, they're obviously running a bit more than that.